"His mania may have been further triggered by the time zone change resulting from his travels from Iran to Mexico, lack of sleep, and the psychological stress of his arrest," wrote Dr. Michael B. First.
A person in a manic state, First wrote, would "have significant difficulty comprehending the circumstances surrounding a particular decision or appreciating the consequences of that decision." An individual in a manic state might "display feelings of invincibility and grandiosity" which may cause them to "enter into agreements that they would not otherwise enter into," he wrote.
First wrote that during his interview, Arbabsiar "displayed a particular cognitive style in which he was very tangential, meandering from topic-to-topic, and it was difficult to keep him on track." Arbabsiar's sister described one episode in which the suspect treated airplane stewardesses, the pilot and passengers seated around him "to expensive bottles of perfume from the duty-free cart because he wanted to make everyone feel good," which First said is consistent with a manic episode. He also reportedly struggled with depression and would only leave his bedroom to chain smoke.
Arbabsiar's friends said after he was charged in October that they did not believe he was capable of pulling off an assassination plot.
U.S. officials charged that the plot was authorized by "elements" of the Iranian military. Another individual charged in the plot -- Gholam Shakuri, an alleged member of Iran's Quds Force -- remains at large.